Sun Microsystems Sun Blade 100, Service Manual

Page: 159 / 222

10-5
C H A P T E R
10
OpenBoot Emergency Procedures
The introduction of USB keyboards with Sun’s newest desktop systems has made it
necessary to change some of the OpenBoot emergency procedures, specifically, the
Stop-N, Stop-D, and Stop-F commands that are available on systems that have
standard (non-USB) keyboards and are not supported on systems that have USB
keyboards. The following sections describe the OpenBoot emergency procedures for
systems with standard keyboards and for newer systems with USB keyboards.
10.1 OpenBoot Emergency Procedures for
Systems With Standard (Non-USB)
Keyboards
When issuing any of these commands, hold down the keys immediately after
turning on the power to your system, and keep them pressed for a few seconds until
the keyboard LEDs flash.
Command Description
Stop Bypass POST. This command does not depend on security-mode.
(Note: Some systems bypass POST as a default; in such cases, use
Stop-D to start POST).
Stop-A Abort.
Stop-D Enter the diagnostic mode (set
diag-switch?
to
true
).
Stop-F Enter Forth on TTYA instead of probing. Use
fexit
to continue
with the initialization sequence. Useful if hardware is broken.
Stop-N Reset NVRAM contents to default values.